Hello, i just want to share that i was in similar case just this week at the time of writing.
My AOR was 07 Nov 2020 and then ADR (Additional Document Request) happened on 25 April 2022 because of Covid19.
The window time that IRCC gave me was only 30 days to submit Medical Report, Schedule A and Police Report since Nov 2020.
Obviously PCC takes time and for me, my PCC was scheduled for collection on 23 May 2022 and it so happens that 23 May 2022 was (or 'will be' at the time of writing this) the same date for deadline submission.
So what i did was:
1) Wrote LOE explaining my case with supporting documents (PCC Payment Proof, Application, Collection Ticket or whatever i feel relevant)
2) Printed the LOE and signed it physically, scanned it as PDF
3) Combined all documents into one PDF and then upload it on the section where I am supposed to upload the PCC. (I did use Webform first but only received generic reply)
Here's the most amazing part, I uploaded on 18 May 2022 (5 days from 23 May, some may argue it's best to submit on the last day. This is also true because the extension they give starts from the day they reply you, not from the original extension date) on 4am Canadian Time and then I got a reply JUST 5 HOURS LATER (9am Canadian Time) saying that they have kindly extended my PCC Submission by 30 days.
Hope my experience can help other people here.